The present invention generally relates to technique for suppressing a difference in pressure between inside and outside of a belt continuously-variable transmission that transmits rotation of an output shaft of an engine to an axle in a vehicle, and more particularly, to an air breather chamber for a belt continuously-variable transmission.
Japanese Patent Laid-open Publication No. H10(1998)-205609 discloses an air breather chamber for a belt continuously-variable transmission. According to structures mainly shown in FIGS. 2 and 4 of Japanese Patent Laid-open Publication No. H10(1998)-205609, an air breather chamber (104) is provided in a region ranging from an upper side to a lateral side of a second shaft (a through-hole portion 74) and a third shaft (a support portion 76) except a part between the second shaft and the third shaft. A first communicating part (106) and a second communicating part (108) each communicating with an inside part of the belt continuously-variable transmission (or an inside part of a casing assembly including a casing) are formed respectively at a middle portion (the upper side of the third shaft) and a lower end (the lateral side of the third shaft) of the air breather chamber (104). The second communicating part (108) has a function of draining working fluid (normally, in the form of oil), having entered into the air breather chamber (104) from the first communicating part (106), outside from the air breather chamber (104) (or returning the working fluid to the inside part of the casing assembly).